1. Field of the Invention
This invention relates to an electrical plug-in busways in which multiple electrically-isolated, conductive busbars are housed in elongated track sections for feeding electricity to take-off devices that may be inserted into the track, and, in particular, to busbar connectors between adjacent track sections.
2. Description of the Prior Art
It is common in factories, shops, offices and other buildings to provide overhead electrical power distribution tracks for providing a convenient source of electricity for lights, machines and other electrical devices in the buildings. Take-off devices are used to tap power from the track to the load apparatus. The load may be anything from a lamp to a three phase electrical machine. It is desirable to be able to insert take-off devices into or remove them from the track at any point along the track itself and make a secure electrical contact with the busbars.
Electrical power distribution tracks are typically comprised of an elongated housing containing multiple electrically-isolated, conductive busbars. Track lighting and continuous plug-in busway are typical of this type of track system. Track sections can be from 2 to 20 feet long. Sections of the track can be joined together by connectors to form long runs for power distribution.
The connectors between track sections must electrically connect the busbars in one track section to the busbars in the adjoining track section or sections. Connectors are also used to feed electrical power to the distribution tracks. Power feed connectors typically plug into the ends of the track sections. Typically, the busbar connector assembly contains conductive bars that make pressure contact with the busbars to provide the electrical connection between track sections.
A variety of busbar connectors are known in the art. One system of busbar connectors uses thin pieces of spring temper metal that is capable of carrying no more than 20 amperes of current. The spring metal is shaped so that the spring temper of the material exerts pressure contact points on the busbars.
Another system uses connector pins and sleeves. Conductive pins are installed between exposed busbars in adjoining track sections. The pins include either a spring pressure means or a screw pressure means. The ends of the busbars are exposed on all sides to receive the connectors or have hollow interiors for installation of the pins.
A third system uses solid metal connector bars and springs or screws for pressing the connector bars against the busbars in adjoining track sections.
An improved busbar connector is needed that substantially increases the contact pressure against the busbars in order to provide a more reliable contact that is capable of carrying higher currents than the prior art connectors. Improved busbar connectors are desired which lower construction costs, eliminate or substantially reduce the possibility of breaking the connector bars, provide insulated pressure screws, and do not require gaps between track sections.